Normal Response of Active GLP-1 Level like Substances to Test Meal in Non-Obese Type 2 Diabetic Japanese Patients with Complications and Receiving Treatments

Abstract

Background: Study has shown no significant differences in basal and postprandial plasma active glucagon-like peptide-1 (p-active GLP-1) levels following test meal (TM) between complication- and treatment-naive non-obese Japanese patients with type 2 diabetes (T2DM) and controls. Methods: In non-obese Japanese patients with T2DM (n=23, group 1) and healthy individuals as control (n=13, group 2), blood levels of plasma glucose (PG), serum insulin (s-IRI), serum C-peptide (s-CPR) and p-active GLP-1 like substances (p-active GLP-1-S) were measured 0, 30, and 60 min after TM (520-560 kcal. 23% fat, 60% carbohydrate and 17% protein). HbA1c levels were also measured in the groups. Patients with mean of 9.2 years disease had various complications and treatment with diet, exercise and/or oral medical drugs except incretin-related drugs for hyperglycemia. Results: There was no significant difference in mean of sex, age, or BMI between groups. Means of HbA1c and basal and postprandial PG with area under curve (AUC), and HOMA-R were significantly higher in group 1 than in group 2. Means of HOMA-β and insulinogenic index after ingestion of TM were significantly lower in group 1 than in group 2. However, there were no significant differences in means of basal and postprandial with AUC levels of s-IRI, s-CPR and p-active GLP-1-S levels between groups. Conclusion: These results indicated that a response of p-active GLP-1-S to TM in non-obese Japanese patients with T2DM associated with a long duration of disease, various complications and various treatments with except incretin-related drugs was similar to those in non-obese healthy individuals.